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981.
Junfang Liu Xiaoming He Jun Xu Guoqing Zhou Shengming Zhou Guangjun Zhao Shuzhi Li 《Journal of Crystal Growth》2004,260(3-4):486-489
Sr2+-doped α-BBO crystals have been grown by Czochralski method. The full-width at half-maximum of (0 0 6) rocking curve is as low as 12 arcsec, which demonstrates the high quality of Sr2+-doped α-BBO crystal. The results of transmission spectra and birefractive indices show that Sr2+ ions do not affect the optical quality and properties of α-BBO. The measurements of DSC–TG and thermal expansion coefficients of Sr2+-doped α-BBO crystal manifest that Sr2+ ions do not influence the thermal properties of α-BBO either. 相似文献
982.
Da-Bing Li Takuya Katsuno Keisuke Nakao Masakazu Aoki Hideto Miyake Kazumasa Hiramatsu 《Journal of Crystal Growth》2006,290(2):374-378
Influence of Si doping on the optical and structural properties of InGaN epilayers with different Si concentrations was investigated in detail by means of high-resolution X-ray diffraction (HRXRD), scanning electron microscope (SEM), Cathodoluminescence (CL) and photoluminescence (PL). It was found that a small amount of Si doping in InGaN could enhance luminescence intensity, improve the crystal quality of InGaN and suppress the formation of V-defects in InGaN. Further investigation by CL showed that V-defects act as nonradiative center, which lower the luminescence efficiency of InGaN. Based on above-mentioned results, one possible mechanism of influence of Si doping on the formation of V-defects in InGaN was also proposed in this paper. 相似文献
983.
Jianfeng Li Meiling Ren Jicheng Qing Yufei Wang Zezhou Liang Ningning Wang 《Molecular Crystals and Liquid Crystals》2019,692(1):74-82
AbstractIn this work, electron transport layers (ETLs) with high charge transfer ability were prepared by doping ZnO nanoparticles with different concentrations of cadmium(Cd). The inverted polymer solar cell based on PTB7-Th: PC71BM as active layer and various concentrations Cd-doped ZnO (CZO) as ETLs were fabricated. The PCE of the device with optimized Cd content in the ZnO film was about 14.7% larger than that of the pure ZnO-based cells. The cadmium-doped ZnO(CZO) is a good candidate to be used as a high-quality transparent electrode in solar cell applications. 相似文献
984.
We analyse the low temperature subband electron mobility in a Ga0.5In0.5P/GaAs quantum well structure where the side barriers are delta-doped with layers of Si. The electrons are transferred from
both the sides into the well forming two dimensional electron gas (2DEG). We consider the interface roughness scattering in
addition to ionised impurity scattering. The effect of screening of the scattering potentials by 2DEG on the electron mobility
is analysed by changing well width. Although the ionized impurity scattering is a dominant mechanism, for small well width
the interface roughness scattering happens to be appreciable. Our analysis can be utilized for low temperature device applications.
相似文献
985.
Sadia Ameen Vazid Ali M. Zulfequar M. Mazharul Haq M. Husain 《Journal of Polymer Science.Polymer Physics》2007,45(19):2682-2687
Binary dopant mixture of (ZrO2/AgI) (v/v) is prepared in different ratios to enhance the conductivity of the synthesized PANI. DC conductivity of (ZrO2/AgI) (v/v) doped PANI samples is measured in the temperature range (300‐400K). The calculated values of pre‐exponential factor (σ0) indicates that conduction is taking place through hopping process due to localized states present near the Fermi level. Structural changes due to interaction of dopant species with PANI are studied through FT‐IR and Photoluminescence characterization. Photoluminescence (PL) spectra of the doped samples occurred in the form of peaks and the intensities of these peaks vary according to the concentration of dopant mixture. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2682–2687, 2007 相似文献
986.
987.
988.
A. Dhar 《Optics Communications》2007,277(2):329-334
The process parameters involved at various stages of solution doping method for fabricating rare earth (RE) doped optical fiber have been systematically investigated to optimize the process conditions and achieve better control over RE incorporation. It is observed that the RE concentration, uniformity and the overall fiber quality are strongly influenced by the solution properties and dipping parameters. The soaking solution needs to be judiciously selected depending on the porous layer characteristics to improve the fiber quality and process efficiency. An interesting observation not hitherto reported is the influence of Al ion concentration in the solution on RE incorporation into the core. The investigation helps to obtain the optimum conditions necessary to produce fibers of given specification and achieve greater reproducibility. 相似文献
989.
酞菁锌掺杂二氧化硅凝胶基质的光谱学特征 总被引:1,自引:1,他引:0
利用溶胶凝胶技术将四磺化酞菁锌 (ZnPcS4)成功地引入到了二氧化硅凝胶基质中 ,制备了均匀掺杂的有机 /无机复合干凝胶。研究ZnPcS4分子在溶胶凝胶过程中紫外可见吸收光谱的变化规律以探索其在复合体系中的存在状态。实验表明 ,在溶胶阶段 ,随着时间的延长 ,紫外可见吸收光谱中单体的吸收峰强度增大 ,说明凝胶中酞菁单体的浓度增大 ;而形成凝胶后 ,随着时间的延长 ,紫外可见吸收光谱中单体的吸收峰强度减小 ,二聚体的吸收峰强度增大 ,说明由于体系结构和微化学环境的变化 ,酞菁分子趋向于聚合。 相似文献
990.
采用第一性原理和密度泛函理论的方法,计算未掺杂、N单掺杂和Ga-N共掺杂纤锌矿结构ZnO的总能、电荷密度和能带结构.总能计算表明,Ga原子的共掺杂使总能极大地降低,从而显著提高杂质N原子在ZnO中的稳定性.电荷密度分布显示,总能的降低主要是Ga-N共掺杂后Ga原子的3d态和N原子的2p态电子之间的强杂化相互作用所致.特别是在Ga原子的负电荷和N原子的正电荷沿c轴排成一线的共掺杂构型中,较大的局域极化场的变化引起价带顶向禁带中的大分裂,降低了N受主的激活能,将空穴的浓度提高了三个量级,有效地提高p型掺杂效率. 相似文献